The present invention relates to an improved Windshield wiper arm for motor vehicles and, more particularly, to a windshield wiper arm in which a blade attached thereto pivots relative to the arm as the wiper traverses its path.
With present wiper arms currently in general use a substantial angular portion of the viewing area of the windshield is left unwiped because the longitutinal axis of the blade is held fixed with respect to the longititutional axis of the arm. Wiper arms like that of the present invention, which provide compound oscillating movement of the blade are known in the prior Art and are currently in use. One such is disclosed in U.S. Pat. No. 3,247,540 by S. J. Howard et al, issued Apr. 26, 1966. With certain applications it is essential that a drag link for producing compound motion be secured so close to the pivot shaft or even within the radius of the pivot shaft so that there will be interference between the drag link and the primary wiper arm. This problem is overcome in U.S. Pat. No. 3,404,423 to S. J. Howard et al, Oct. 8, 1968 by mounting a disk on the pivot shaft housing eccentrically to the pivot shaft and journaling said disk in a bearing ring secured to the inner end of the drag link. This enables the oscillating axis of the drag link to be very close to the pivot shaft or even within the radius of the pivot shaft. However, as the wiper traverses its wiping path the curvatures of modern windshield causes the drag link to gyrate. The Howard et al. U.S. Pat. No. 3,404,423 has no provision for freeing the drag link for gyrating motion.